Milk fever is a metabolic disease occurring soon after freshening (calving) in cows. It is characterized by a drastically decreased calcium concentration in the blood. As a result of hypocalcemia (low blood ionized calcium concentrations), the cow may lose muscle tone, making her unable to stand or rise. It is known that milk fever can be effectively treated through intravenous administration of calcium gluconate, but it is also known that cows, once having suffered milk fever, have economic losses in terms of their overall health, effective yield of milk, susceptibility to other disease complexes such as Ketosis, Displaced Abomasum, Retained Placenta, increased susceptibility to Mastitis, etc.
It has been discovered that milk fever can be effectively treated and/or prevented by feeding dairy cows during the close up period (14 to 21 days pre-calving) a diet containing substantial amounts of negative ions (i.e., anionic salts). See Beede, Feed Management, Jun. 1992, Vol. 93 No. 6 pp.28-31. While it is not known precisely why an anionic diet works to effectively prevent milk fever, it is theorized that in order to physiologically neutralize the negative charged diet, a reduction in blood PH occurs which increases mobilization of bone calcium. Therefore, at parturition the potential for hypocalcemia is reduced because the pathways for calcium reabsorption from the bone are active. As Dr. Beede states in his article, the exact mechanism by which a negative cation-anion balance (here described as dietary cation-anion difference (DCAD)) influences metabolism in dairy cattle is unclear. Nevertheless, the end result of feeding anionic salt feed additive is that blood calcium concentrations are maintained near normal and the metabolic machinery to increase blood calcium is readily functionalized. This situation can be immensely helpful to the pre-partum cow.
As a result of the above-described knowledge, many in the feed industry have developed anionic salt feed additives that are promoted for feeding to a dry cow prior to freshening. The typical salt treatments as now commercially available contain substantial amounts of sulfate ions and of ammonium chloride and ammonium sulfate with the conventional thinking that since chloride and sulfate are essential and since ammonium is a weak cation, the use of these salts will favor a negative or anionic balance. While indeed they do favor a negative or anionic balance, these products are not found palatable by the cows. The high amount of sulfate anion and ammonia make the product unpalatable. As a result, when free choice fed to animals, despite the fact that the composition has the ability to help the cow, the composition is not very effective because the animal simply will not eat them due to their unpalatable nature.
In the past elemental sulfur has been disregarded as a potential source of needed sulfur because early in vitro research indicated poor availability of elemental sulfur for bacterial fermentation. However, in the combination of this invention elemental sulfur, which is more concentrated than sulfate, is bioavailable and is after ingestion converted to bioavailable format.
Accordingly, it is a primary objective of the present invention to prepare an effective anionic feed additive which has the proper cation-anion balance (DCAD) but which is also highly palatable and has significantly reduced levels of ammonium salt additives and which uses free sulfur as a sulfate source.
Another objective of the present invention is to provide a method of preventative treatment for milk fever comprising administering to a dry cow a small but calcium mobilizing effective amount of an anionic salt feed additive that is of significantly reduced levels of ammonium salts and which contains elemental sulfur as opposed to sulfate as the predominant sulfur source.
Another objective of the present invention is to provide a preventative treatment feed additive DCAD balanced composition which will achieve the above-described results.
Another objective of the present invention is to provide a composition which can be effectively and economically produced, a composition which can be pelletized and if desired free choice fed either alone or as part of a total mixed feed ration, and a composition which the cattle themselves regard as highly palatable.
The method and means of accomplishing the above objectives as well as others will become apparent from the detailed description of the invention which follows hereinafter.